The present invention is directed to an improved credit card and method of making the same. The credit card has a clear, scratch resistant metallic surface.
The use of credit cards has become increasingly wide spread. Efforts have been made to provide these cards with attractive, distinctive appearances to identify and promote the company or other entity issuing the cards. Recently, the application of holographics to credit cards has been popular for these reasons. The attractiveness of a metallic surface is generally recognized but such surfaces with printed graphics would be readily scratched and lose their attractiveness on a credit card with normal use of the card.
It is known to apply a clear vinyl film such as PVC over the printing on the white vinyl core, also of PVC, of a credit card under heat and pressure in a hydraulic laminating press to protect the surface of the card including the printing thereon. However, heretofore it has not been possible to apply such a protective film over a metallic surface applied on the plastic core of a credit card without encountering problems in breakage of the thin metallized surface and/or lack of clarity in the overlaminate. Conventional offset lithography printing of a thin metallized surface on a thin plastic substrate such as a credit card is also not practical, especially in an automated process, since the details of the graphics, e.g., fine lines etc., tend to blur. Processing a laminate of a plastic substrate with a metallized surface is also problematical because the laminate in effect becomes a capacitor for storing static electricity generated during processing such as printing.
An object of the present invention is to provide an improved credit card and a method of making the same which avoid the aforementioned problems. More particularly, an object of the invention is to provide a credit card and a method of making the same whereby the card has an attractive scratch resistant metallic surface which remains unbroken during manufacturing. Another object is to provide a protected metallized surface on a credit card which is clearly visible. A further object of the invention is to provide a method of forming a credit card having a protected metallized surface wherein clearly legible printed information can be readily provided on the metallized surface of the card.
These and other objects are attained by the method of making a credit card with a scratch resistant metallic surface according to the invention, the method comprising the steps of providing a plastic substrate, providing a metal containing layer on at least a first surface of the plastic substrate and providing the metal containing layer with a transparent film to protect the metal containing layer without breaking the layer. The metal containing layer is preferably in the form of a metallic foil which is bonded to the first surface of the plastic substrate during the applying step. One side of the foil is initially adhered to a thin film carrier via a release agent. An outer, opposite side or surface of the foil to be bonded to the first surface of the plastic substrate is coated with a heat-activated adhesive. The foil is bonded to the first surface of the plastic substrate under the application of heat and pressure in a hydraulic laminating press, for example, to adhesively bond the foil to the first surface of the plastic substrate and release the foil from the carrier film. The first surface of the substrate is press polished prior to transferring the metal containing layer thereon.
The metal containing layer provided on the first surface of the plastic substrate is printed to form graphics, e.g., letters, pictures, etc., before the transparent film is provided thereon. According to the method of the invention the graphics are printed by silk-screen printing on the metal containing layer using with an ultraviolet curable ink which is cured immediately after being applied to the layer by directing ultraviolet light on the ink. The method further includes the step of eliminating static electricity from the layer and plastic substrate during the printing to facilitate the printing operation. This is accomplished by the application of ionized air to the plastic substrate and metallized layer and the provision of grounded, conductive tinsel near the substrate in the printing apparatus.
According to the disclosed embodiment, the transparent film is provided on the metal containing layer by coating the printed metal containing layer with an ultraviolet curable varnish and curing the varnish by directing ultraviolet light on it. Alternatively, the transparent film can be a clear polyester film which is adhesively bonded to the metal containing layer using a clear heat-activated adhesive, particularly a polyethylene adhesive. More particularly, the heat-activated adhesive on a surface of the clear polyester film is heated and then bonded to the first surface of the plastic substrate by conveying the substrate and film between opposed nip rollers to press the film against the metal containing layer on the substrate.
The plastic substrate is preferably in the form of a large sheet containing a plurality of credit cards. The individual credit cards are die cut to card size from the sheet after the step of providing the metal containing layer with the transparent film. Identifying information means is then located on each card. In the disclosed form of the invention, the identifying information means is a magnetic tape which is attached to the card on a second surface of the plastic substrate opposite the first surface of the substrate by a known hot stamping process, a roll or heat transfer process or a laminating process.
The improved credit card made by the method of the present invention comprises a plastic substrate in the form of a card, a metal containing layer having printed graphics thereon overlayed on at least one surface of the plastic substrate and a transparent film over the metal containing layer. The metal containing layer is bonded to the first surface of the substrate and preferably covers at least substantially the entire first surface of the substrate. The metal containing layer is a metallic foil formed from aluminum or an aluminum alloy, for example, which may be colored to have a gold, silver, red, green, blue or other colored appearance. The transparent film which is bonded to the metal containing layer is preferably a clear, ultraviolet cured varnish. In the disclosed form of the invention, the metal containing layer has printed graphics in ultraviolet curable ink silk screened thereon beneath the transparent film on the metal containing layer. A second surface of the substrate opposite the first surface also bears printed graphics and is overlayed with a transparent vinyl film with a magnetic tape being attached thereto for carrying identifying information.